Soluble oil base



Patented Aug. 1,1950

SOLUBLE OIL BASE Knapel F. Schiermeier, Alton, 111., as'signor to ShellDevelopment Company, San Francisco, Calif a corporation of Delaware NoDrawing. Application April 18, 194'), Serial No. 742,465

This invention relates to tions having excellent rust and/or corrosioninhibiting properties. More particularly, this invention pertains to anall-purpose soluble oil composition which is applicable as a rustinhibitor for ferrous metals, and/or as a coolant and lubricant formetal working of ferrous and nonferrous metals.

Metallic surfaces exposed to moisture, corrosive fluids and the like arereadily attacked and rust or corrode. Such conditions are usuallyencountered when transporting metal articles over bodies of water, orwhen storing them or exposing them for long periods of time to highlyhumid conditions. Metals which are quenched or immersed in or sprayedwith aqueous mediums, particularly electrolytic solutions, becomesusceptible to rusting and/or corrosion due to the strong afilnity andadherence of the moisture for the metal surface. Corrosion of metals isalso caused by acids formed during combustion of halides in ethyl fluidsor decomposition of lubricants during operation of internal combustionengines and the like. Handling of metals also causes corrosion and isgenerally referred to as fingerprint corrosion. 'At elevatedtemperatures the above conditions become aggravated and corrosionactivity is enhanced due to the increased chemical activity of moistureand corrosive fluids towards the metal.

Various substances have been tried for preventing rusting and/orcorrosion of metals. In the majority of cases such compositions compriseoleaginous bases such as mineral lubricating oil, fatty oils, greasesand the like containing minor amounts of corrosion inhibitors such asnatural or synthetic resins or waxes, cellulose esters or ethers, woolfat, paraflin wax, resinates, preferably the barium, magnesium andaluminum resinates; metal salts of polyalkyl diphenol sulfides; alkylenepolycarboxylic acids, 1. e. alkylene succinic acid; substituted fattyacids, 1. e. mercapto stearic acid and the like. In the majority ofcases such compositions have proved to be of little value as rust and/orcorrosion inhibitors due to their relative inability to displacemoisture and other adhering contaminants from metal surfaces as well astheir inability to inhibit decomposition or deterioration of the mediumin which they are dispersed, especially at elevated temperatures andtheir short active life.

It has now been discovered that soluble oils of the type which willhereinafter be disclosed are superior to any known aqueous andnon-aqueous rust inhibiting compositions. The active components ofcompositions of this invention possess a greater affinity for metalsthan does water and readily displace it from the metal surface. Inaddition they possess excellent spreading and wetting characteristicsforming on ferrous and soluble oil composl- 7 Claims. (01. 25H3-2) ingprotective film which is impervious to moisture and/or corrosive fluidsand is not easily ruptured. Other components of this composition possessthe property of readily adsorbing displaced moisture forming stableemulsions and thereby removing moisture as a future potential corrosioninhibitor in event the protective film is ruptured. Certain ingredientsof this invention possess the property of neutralizing acidic materialsas they are formed thereby inactivating them and'rendering themharmless.

In order that the active rust inhibiting constituents of this inventionexert their maximum influence and operate-at maximum efliciency theymust be blended in such proportions as to possess good emulsiilability,good solubility in the base stock in which they are dispersed and resistoxidation. By coupling or bridging the oil-soluble ingredients and thewater-soluble ingredients with blends of materials of graduatedsolubility which range from compounds miscible with water at one end tocompounds miscible with oil at the other end, a stable emulsion can beobtained, the active components of which are free to function asdesired.

It is an object of this invention to provide a new rust and/or corrosioninhibiting compositing when applied over metal surfaces. Another objectis to provide soluble oil compositions having excellent water displacingand rustproofing properties. Still another object is to provide solubleoil compositions which inhibit rusting of metals due to handling or whenin contact with corrosive fluids. A further object is to provide solublerust inhibiting compositions which are resistant to adverse conditionsof temperature. A still-further object is to provide soluble oilcompositions for inhibiting rusting of metals which can be readilyapplied and easily removed. Still another object is to provide rustinhibiting soluble oils suitable for metal like.

These and other objects are accomplished according to the present,invention by preparing a solubleoil containing highly polar compounds atleast one of which is an oil-soluble alkali metal salt of petroleumsulfonic acid and another is a water-soluble salt of a hydroxy fattyacid having at least 10 carbon atoms and preferably between about 16 to18 carbon atoms. These salts are selected so that they are mutuallymiscible with each other, and are bridged with specific coupling andstabilizing agents so as to produce a stable, non-corrosive emulsionwhich is readily miscible with liquid petroleum hydrocarbon. Thesulfonate constitutes between about 40% and about and the water-solublesalt of a hy droxy fatty acid constitutes between'about. 10%

and about 25%-by weight of the composition,

non-ferrous surfaces a continuous strong adherso Suitable sulfonates,particularly the sodium cutting, working and the anaasa salts ofoil-soluble petroleum suli'onic acids are obtained by treating suitablepetroleum hydrocarbon fractions with sulfuric acid. Petroleum fractionswhich can thus be treated to obtain desired sulfonates are gasoline,naphtha. kerosene, furnace oil, neutral oil, turbine oil and generallymineral oils which contain around about or higher aromatic constituents.For example, a turbine oil having a Saybolt Universal viscosity at 100F. of from about 400 to 540 seconds can be treated with fuming sulfuricacid, preferably in small increments. After a calculated amount ofsulfuric acid has been added to the oil, the sludge which forms isremoved and the acid-treated oil containing dissolved oil-solublesulfonic acid is neutralized with a solution of sodium hydroxide. Theaqueous alkali solution is removed from the mixture and the sodium saltsof petroleum sulfonic acid extracted with alcohol. The alcohol layercontaining the sulfonates can be removed by distillation or by any othersuitable means.

Modifications to the above procedure can be made by removing acid sludgeafter each added increment of sulfuric acid, rather than removing itafter the entire required amount of acid has been added. Also thesulfonic acid can be removed before neutralization rather than after asindicated above. If this is done, it is preferable to give theacid-treated oil a clay treatment so as to remove inorganic esters ofsulfuric acid and other impurities so as to prevent formation ofinorganic salts. Clays which are particularly suitable are highlyabsorbent clays such as Attapulgus clay, floridin, bentonite, bauxite,fullers earth, etc. Still another modification in preparing pureoil-soluble sulfonates is to add to the sludge free acid-treated oil asolvent such as benzol, carbon tetrachloride and the like andneutralizing said mixture with a caustic solution. The spent causticsolution is removed and the solvent distilled off, leaving asubstantially pure sulfonate in an oil mixture. The product can be airblown and dehydrated to remove impurities. Sulfonates prepared fromturbine oils by the above means generally have a molecular weight offrom between about 425 to 600. Sulfonates which have a molecular weightbetween about 540 to 570 are preferred as additives in this inventionand they usually contain from about 45% to about 70% of sodiumsulfonate; about 20% to 40% mineral oil; about 7% to 10% water and from2% to 5% impurities. Other salts which can be used to produce thesulfonates are lithium, potassium, cesium and the like.

The water-soluble salts of hydroxy fatty acids having at least 10 carbonatoms are obtained by saponiilcation of hydroxy saturated andunsaturated fatty acids such as dimethyl hydroxy caprylic acid, dimethylhydroxy capric acid, hydroxy physetoleic acid, ricinoleic acid,ricinelaidic acid, hydroxy stearic acid, linusic acid, sativic acid andthe like with an alkali metal such as sodium, potassium or byneutralizing said acids with ammonium; alkyl and alkylol amines, e. g.ethyl and diethyl amine, propyl and isopropyl amine, butyl and isobutylamine. diethylaminopropylamine, ethanolamine, ethyl and diethyl ethanolamine, butyl ethanol amine, d1- butylaminoethanol and. the like. Amongthe preferred salts are ammonium and sodium ricinoleate.

To stabilize mixtures of oil soluble alkali petroleum sulfonates andwater soluble salts of hydroxy fatty acids coupling agents are added inlected from the. group consisting of alkylene glycol, glycol mono-alkylethers, diglycol monoalkyl ethers and aliphatic alcohols. Specificallythe following coupling agents can be used:

Ethylene glycol mono-ethyl ether Ethylene glycol mono-propyl etherEthylene glycol mono-n-butyl ether Ethylene glycol mono-isobutyl etherEthylene'glycol mono-tertianylbutyl ether Ethylene glycol mono-hexylether Propylene glycol mono-ethyl ether, etc. Diethylene glycolmono-methyl, ethyl, n and isopropyl ethers, Diethylene glycol mono-butylether Diethylene glycol mono-decyl ether Dipropylene glycol mono-ethylether Dipropylene glycol monc-isopropyl ether Dipropylene glycolmono-isoamyl ether Dipropylene glycol mono-heptyl etherEthylene-propylene glycol mono-ethyl ether Ethylene-isobutylenemono-isopropyl ether, etc. Ethylene glycol, propylene glycol, hexyleneglycol, etc., isopropanol. butanol, etc. The coupling agents can be usedalone or in mixtures.

To aid in forming a, stable emulsion minor amounts of from 1% to 5% byweight of glycerin can be added to the mixture. The addition of glycerindoes not only facilitate emulsiflability but prevents separationespecially at low temperatures.

To improve the rust inhibiting and lubricating properties ofcompositions of this invention, particularly when they are used as metalworking lubricants, a. minor amount of fixed fatty oils and/or waxespreferably not exceeding 10% by weight and more particularly when keptin the range of from about 4 to 10% can be admixed. Fixed fattymaterials which can be used are animal, vegetable and marine oil and/orwaxes and include neats-foot oil, horse fat, beef tallow, mutton tallow,degras, lard oil; olive oil, peanut oil, castor oil, cocoanut oil, palmoil, Japan wax, cottonseed oil, kapok oil, sesame oil, corn oil, colzaoil, sperm oil, seat oil, whale oil. dolphin oil. menhaden oil, sardineoil, codliver oil, etc.

When fixed fatty oils are added it is advisable to add small amounts ofa germicidal agent so as to inhibit bacterial growth and fermentation.Emulsions containing fixed oils are very susceptible to deteriorationespecially when used at elevated temperatures for long periods of time.Such emulsions develop an extremely strong, foul and undesirable odorrendering them practically useless. Bacterial growths also cause metaldiscoloration and are a constant danger to the health of the user. Theaddition of a germicidal agent such as Formalin (aqueous solution ofapproximately 40% formaldehyde) or phenolic compounds e. g. phenol,-chlor para. phenyl phenol, o-phenyl phenol and the like are verybeneficial in not only inhibiting bacterial growth but in preventingdiscoloration of metals and deterioration of emulsions. The amount ofgermicidal agent used generally does not exceed 5% by weight.

Soluble oils of this invention can be made simply and eiiiciently,requiring no special technique or equipment. To obtain a stable product,however, care should be taken to adhere to certain proportional limitsof each ingredient auasss used to make up the soluble oil. The productcan be made by first mixing the water soluble ingredients together andthen slowly adding the oil-soluble ingredients under constant agitation.No external heat is required because of the heat of neutralization andreaction although if desired the emulsion can be made using heat tofacilitate the process. For example, calculated amounts of water, sodiumhydroxide solution, Formalin, glycerin and ethylene glycol ethyl etherare admixed and agitated in a suitable vessel. A

required amount of ricinoleic acid is slowly added and the mixtureagitated until a soap of sodium ricinoleate forms in the solution. Tothis mixture is added, sodium petroleum sulfonate, and if desired, asmall amount of a fatty oil such as ex- Sand blasted panels of mildsteel were dipped five times during a period of 30 seconds into aqueousemulsion of test compositions as noted in the following table. Thepanels were then allowed to remain vertically to drain for hours'under.

ordinaryroom temperature. The panels were then placed in a humidifierchamber in which the temperature was maintained at 100 F. and thehumidity at 100 F. The time for the panels to develop rust was observedand recorded as the resistance life of the composition.

tra winter strained lard oil and the entire mixture agitated until ahomogeneous mass is ob- Composition fi {g tained.

A specific example henceforth referred to as 20 1 Mineral lubricatingoil+l0% of Composition 10 minutes. composition A of a soluble oilobtained by the X above method comprised: 2 Mmeraliubricatmg oil+l0% ofComposition A. l00 hours.

Percent weight g xid .itzerztr'siazets;i13m mm So ium y ro e Formalin(approx. HCHO) 2.2 shed test Glycerin r 6.1 Polished steel panels weredipped in aqueous Ethylene glycol ethyl ether 5.8 emulsions of testcompositions specified in the Ricinoleic acid 16.6 fOIIOWiIig table, for10 seconds and exposed to Sodium sulfonate (100%) 46.1 30 the atmospherefor 5 days. The panels were then Extra winter strained lard oil 9.0inspected for signs of rust.

Amount Composition A Composition X Composition Y 1 Composition Z I 57aqueous emulsion--- No Rust Heavy Rust...- Very Heavy Rust. Very HeavyRust. 3 0 aqueous emulsion Light Rust which was very thin do (in DO andeasily removed by wiping. 1% aqueous emulsion--. do do do Do.

1 Composition Y comprises: 70.5% mineral oil, 27.57 sodium sulionate,20% water and 0.5% o-phenyl phenol. 1 Composition Z comprises: 75%mineral oil and 25 o of a -50 mixture of sodium sulionate and sodiumrosin soap.

Soluble oils of this invention can be used per se or preferably blendedwith a suitable petroleum base in amounts varying from 1 to 30% andpreferably between about 10 to 20% by weight depending upon thepetroleum base and intended use of the composition. Petroleum productswhich can be used as bases are: kerosene, mineral seal oil, gas oil,petroleum naphtha cuts, mineral spirits, aromatic solvents, minerallubricating oil, petroleum waxes and the like. The additive mixture canbe admixed with a suitable petroleum base by heatingthe base to aroundabout 100 F. and slowly adding the additive mixture under constantagitation until a homogeneous mass is obtained. A general formula ofbase compositions of this invention contain the followin components byweight:

Per cent Petroleum base (mineral lubricating oil) 70-90 Additive mixtureof this invention, 1. e.

composition A 1-30 Water 0.5-4

Base compositions as noted may be diluted with a major amount of wateror other aqueous medium in order to obtain desired rustproofing andmetal working lubricants. Excellent cutting emulsions are obtained byusing about 25% of the base and diluting it with about 75% water. Ifdesired, in some cases the base may be diluted with as much as 100 to200 parts of water.

The efficiency of compositions of this invention as rust inhibitors andmetal working lubricants Compositions of this invention make excellentcutting fluids because of their outstanding cooling and lubricatingproperties. In metal working operations such as cutting, reaming,drilling, threading, drawing, etc., extremely high temperatures andpressures are developed causing failure of the cutting or working toolor undesired finish of work piece or both. Machining failure isgenerally due to build-up microscopic metal particles formed duringmachining and which weld and build up on the tool surface. This build-upedge due to great compressibility forces exerted on the tool break 011,damaging the tool and work piece.

Eifective coolants and lubricants for metal working must possess a highdegree of chemical reactivity with the machined metal surface so as toform thereon a protective film capable of withstanding extremepressures. They must also be free flowing so as to readily enter thecrack formed between the tool and workpiece and act steel ballsarrangedin pyramid formation; The

top ball is rotated by spindles against the three bottom balls which areclamped in a stationary. ball holder. The balls are immersed inthe testcomposition. Tests were run at 700 R. P. M. under 14.1 kg. load at 30 C.The diameters of 1. 10% soluble oil blend of composition A 0.49

2. 10% soluble oil blend of composition X--- 0.63

' 3. Aqueous emulsion of 10% of,a soluble oil blend of composition A in90% within... 0.60 4. Aqueous emulsion of 10% of a soluble oil blend ofcomposition X in 90% water 0.87 Distilled water 0.96

Other additives can be added to compositions of this invention in orderto improve their performance. Thus extreme pressure additives such assulfurized and sulfurized-halogenated olennic hydrocarbons and/or fattyoil, e. g. sulfurized sperm oil, sulfurized lard oil; sulionated castoroil can be used. Also oiliness agents such as oleic and stearic acids,soaps, etc; anti-foaming agents such as dicetyl silicone; anti-oxidantssuch as phenolic and amine compounds and the like can be added tocompositions of this invention gen erally in amounts of around about 0.5to 5% by weight.

' Compositions of this invention can be easily modified to meet requiredconditions for combating rust. Thus in the case of protection offurnished metal articles the additive agents of this invention can bedispersed in a light hydrocarbon which evaporates readily and leavesbehind a protective coating. Where metals are exposed to heavy rains andhighly humid conditions they can be immersed in compositions of thisinvention having as a base a heavy oil or wax which can be removed byflushing or wiping.

Percent weight Water 11.8 Sodium hydroxide 2.4 Formalin (approx. 40%HCHO) 2.2 Glycerin 6.1 Ethylene glycol ethyl ether 5.8 Ricinoleic acid16.6 Sodium sulfonate (100%) 46.1 Extra winter strained lard oil 9.0

said constituents being blended with from 70% to 90% of a minerallubricating oil.

2. A lubricating emulsion comprising an aqueou medium having solubilizedtherein a minor amount suflicient to impart rust-inhibiting properties,a composition which consists essentially of to 90% mineral oil incombination with amount suilicient to impart rustdnhibiting properties,a composition which consists essentially of 70% to mineral oil incombination with from 30% to 10% of a base comprising 40% to 65% of anoil-soluble sodium salt of petroleum sulfonic acid, substantially 10% to25% oi sodium ricinoleate, from 4% to 10% of a mixture of ethyleneglycol mono-ethyl ether, and glycerin and the balance being water.

4. A lubricating emulsion comprising an aqueou medium having solubilizedtherein a minor amount suflicient to impart rust-inhibiting properties,a composition which consists essentially of 70% to 90% mineral oil incombination with from 30% to 10% of a base comprising 40% to 65% of anoil-soluble sodium salt of petroleum sulfonic acid, substantially 10% to25% of ammonium ricinoleate, from 4% to 10% of a mixture of ethyleneglycol mono-ethyl ether, and glycerin and the balance being Formalin.

5. A lubricating emulsion comprising an aqueous medium havingsolubilized therein a minor amount sufficient to impart rust-inhibitingproperties, a composition which consists essentially of 70% to 90%mineral oil in combination with from 30% to 10% of a base comprising 40%to 65% of an oil-soluble sodium salt of petroleum sulfonic acid,substantially 10% to 25% of sodium hydroxy stearate, from 4% to 10% of amixture of ethylene glycol mono-ethyl ether, and glycerin and thebalancebeing Formalin.

6. A lubricating emulsion comprising an aqueous medium havingsolubilized therein a minor amount of from 1% to 30% of a compositionwhich consists essentially of 90% mineral oil in combination with about10% of a base comprising 65% of an oil-soluble sodium salt of petroleumsulfonic acid, substantially 25% of a watersoluble sodium salt of ahydroxy fatty acid having at least 10 carbon atoms, from 4% to 10% of astabilizing agent from the group consisting oi aliphatic alcohol,di-glycol mono-alkyl ether, and glycol mono-alkyl ether and the balancebeingwater.

17. An oil base soluble in an aqueous medium adapted for use as a rustinhibitor and metalworking lubricant containing the followingconstituents in the following approximate proportions:

9 Percent weight Water 11.8 Sodium hydroxide 2.4 Foi'malin (approx. 40%HCHO) 2.2 Glycerin 6.1 Ethylene glycol ethyl ether. 5.8 Hydroxyaliphatic hydrocarbon carboxylic acid having 18 carbon atoms and notmore than one double bond in the molecule 16.6 Sodium petroleumsulfonate (oi1-soluble) 46.1 Extra winter strained lard oil 9.0

10% to 30% of the composite of said constituents being blended with from70% to 90% of a liquid petroleum oil base.

KNAPEL F. SCHIERMEIER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,817,599 Adams Aug. 4, 19312,097,085 Fabian Oct. 26, 1937 2,338,522 Liberthson Jan. 4, 19442,421,158 Myers May 27, 1947

7. AN OIL BASE SOLUBLE IN AN AQUEOUS MEDIUM ADAPTED FOR USE AS A RUSTINHIBITOR AND METALWORKING LUBRICANT CONTAINING THE FOLLOWINGCONSTITUENTS IN THE FOLLOWING APPROXIMATE PROPORTIONS: